Gauges with electroluminescent lighting



June 25, 1963 R. ZARGARPUR GAUGES WITH ELECTROLUMINESCENT LIGHTING Filed April 25, 1960 5 Sheets-Sheet 1 FIG. I.

iNVENTOR ROUHOLAH ZARGARPUR VATTORNEV June 25, 1963 R. ZARGARPUR GAUGES mm ELECTROLUMINESCENT LIGHTING 5 Sheets-Sheet 2 Filed April 25, 1960 FIG. 6.

INVENTOR RouHoLAH ZARGARPUR ATTORNEY June 25, 1963 R. ZARGARPUR GAUGES wm: mscmcwmmascsm LIGHTING Filed April 25. 1960 5 Sheets-Sheet 3 INVENTOR ROUHOLAH ZARGARPUR 55x In, t.

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amass wrm zmc'mowumasczur LIGHTING Filed April 25, 1960 5 Sheets-Sheet 4 I NVE NTOR ROUHOLAH ZARGARPUR ATTORNEY June 25, 1963 R. ZARGARPUR 3,094,970

GAUGES WITH ELECTROLUMINESCENT LIGHTING Filed April 25, 1960 5 Sheets-Sheet 5 INVENTOR 159 ROUHOLAH ZARGARPUR ATTORNEY Unite States Patent 3,094,970 GAUGES WITH ELECTROLUMINESCENT LIGHTING Rouholah Zargarpur, River Forest, 11]., assignor to Stewart-Warner Corporation, Chicago, III., a corporation of Virginia Filed Apr. 25, 1960, Ser. No. 24,576 4 Claims. (Cl. 116129) This invention relates to gauges whose indicating indicia are illuminated by electroluminescence, commonly termed panelescent illumination. More particularly, it relates to the encrgization of a movable gauge pointer which is illuminated by electroluminescence.

The term electroluminescence has been given to the phenomenon of the emission of light from a phosphor subjected to a changing electric field. To produce this phenomenon, a suitable phosphor is placed between two conductors, at least one of which is translucent or transparent and the two conductors connected to a changing electric potential giving rise to a changing electric field therebetween. Light is emitted from the excited phosphor and passes through the transparent or translucent conductor. structurally, such a light device resembles a condenser having a translucent or transparent plate, the phosphor being analogous to the condensers dielectric.

Electroluminescent lamps and methods of making them are now well known in the prior art, although this phenomenon is a comparatively recent development. As illustrating the basic phenomena and also the method of manufacture of panelescent devices that differ from the usual fluorescent lamps in which the voltage or field is placed across a gas and the radiation from the gas used to excite a phosphor, reference may be had to the Mager Patents Nos. 2,566,349 and 2,624,857, issued September 4, 1951 and January 6, 1953, respectively.

In one embodiment of the invention the improvements comprising this invention have been applied to a speedometer and an associated odometer.

In another embodiment of the invention the improvement is applied to an ammeter of superior design which includes a pivotal mounting arrangement therein to make both pointer connections for panelescent lighting.

A further embodiment of the invention is applied to a thermal type gauge in which a split shaft construction is utilized.

Still a further embodiment of the invention is applied to still another type of thermal gauge which has sufiicient power to move the pointer without affecting its accuracy or reliability even though the pointer must support the current transmitting wire which is secured to a fixed terminal on the dial face.

In the drawings:

FIG. I is a front view of an automobile speedometer whose moving pointer is illuminated by panelescence;

FIG. 2 is a partial longitudinal cross-sectional view of the speedometer taken along line 22 of FIG. 1;

FIG. 3 is an enlarged view along line 3-3 of FIG. 2, showing the details of the panelescent pointer connection of FIGS. 1 and 2;

FIG. 4 is an enlarged partial cross-sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a further enlarged plan view of a terminal lug which receives power from an external source;

FIG. 6 is a cross-section of the lug taken along the line 66 of FIG. 5;

FIG. 7 is a front view of an automotive gauge illuminated by panelescence according to a second embodiment of the invention partially broken away to show the operative features of the gauge;

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FIG. 8 is an enlarged partial cross-sectional view of a part of the gauge taken along the line 88 of FIG. 7;

FIG. 9 is a front view of an automotive gauge illuminated by panelescenee according to a third embodiment of the invention partially broken away to show the operative features of the gauge;

FIG. 10 is an enlarged partial cross-sectional view of a part of the gauge taken along the line 1010 of FIG. 9;

FIG. 11 is a partially broken-away front view of an automotive gauge illuminated by panelescence according to a fourth embodiment of the invention;

FIG. 12 is an enlarged side view of the gauge of FIG. 11 partially broken away to show the operative features of the gauge; and

FIG. 13 is a further enlarged view taken along line 13-13 of FIG. 11.

Referring now to the embodiment illustrated in FIGS. 1 to 6 of the drawings, FIG. 1 illustrates an automobile gauge including a speedometer and an associated odometer. As illustrated in FIG. 2, the gauge includes a dial face 10 which is coated with electroluminescent phosphors in accordance with the teachings of the aforementioned Mager patents. A lead 11 supplies an electric signal to energize the coating and illuminate the dial across which sweeps a pointer 12 illuminated by panelescent lighting, as hereinafter described. The pointer is actuated by a suitable mechanism 14 whose output torque is responsive to a condition to be sensed and also includes an odometer mechanism 16. The rotating counters of the odometer may also be illuminated by panelescence from surface 17 which has suitable coatings to be energized via a lead 15. The actuating mechanism 14 may be of any conventional construction, as for example that illustrated in U.S. Patent 2,649,559 to Wargo. As shown in FIG. 3, the lower end of pointer 12 is clampingly received by a bracket 15 whose lower portion carries a counterweight 19. The bracket 15 is connected by a bushing 18 to a pointer shaft 20. As illustrated in FIG. 4, the shaft 20 leads to the actuating mechanism 14. The shaft 20 is rotatably supported by a metallic bushing 22 threadedly secured to a supporting bracket portion 24 of the gauge. The numeral 26 denotes a spring tension clip formed of insulating material. The clip is apertured for the reception of the bushing 22 and in cludes a terminal 28 which leads to extending terminal portions 29 and 30. The outer end of 29 clampingly receives the outer convolution of a spiral tension spring 32 the inner whorl of which is connected to a metallic retainer ring 34. The jaws of terminal 30 receive a lead 37. An insulating bushing 36 clamps the shaft 20 and has an axial protrusion fitting into the ring 34. A lead 38 connects a conductive and transparent coating 39 on pointer 12 to the metallic ring 34. A suitable electroluminescent phosphor 39a such as disclosed in the Magcr patents lies below outer translucent or transparent conductive coating 39 and hence is situated between the metallic pointer body of pointer 12 and the outer coating 39. A nut 27 is threaded on the bushing 22 and clamps the clip 26 to the gauge support portion 24.

It is thus seen that by way of the construction illustrated, two connections to the pointer 12 are formed in the following manner. One connection is by way of lead 37 to the jaws 30, then to terminal 28 and thence to tension spring 32. From spring 32 the connection progresses to ring 34, lead 33 and the outer coating 39. The second connection is through the metal body of pointer 12, bracket 15, bushing 18, shaft 20, and thence to the body of the gauge.

The operation of this embodiment of the invention is as follows. Upon energization of the torque mechanism 14, the shaft 20 rotates against the bias tension of spring 32 carrying the pointer 12 across the dial face 10. The tension on pointer 12 may be varied by rotation of clip 26 about bushing 22. By the above arrangement, the torque necessary to turn the pointer is in no way infiuenced by the connection to the pointer coating 39. It will be noted that the above two connections are provided to the pointer in such a manner that angular movement of the pointer is resisted only by the spring 32 and not influenced by the lead 38.

Referring now to the embodiment of the invention illustrated in FIGS. 7 and 8, the numeral denotes a sector-shaped gauge body of an ammeter having a face 41 which is coated with electroluminescent materials and energized by lead 43 so as to be illuminated by panelescence. The body 40 includes a cup-shaped circular recess 42 receiving the actuating mechanism now to be described. The numeral 44 denotes a bracket whose upper end is secured to the case 40 below the face by means of a screw 46 and a detent 48 adapted to be received in a complementary recess in body 40. The lower end of the bracket 44 carries a metal bearing screw 47 one end of which pivotally supports a shaft portion 49. One end of the shaft portion 49 is rigidly secured into a cylindrical block of insulating material 50'. A metal bracket 52 is secured to the shaft portion 49 and block 50 at one end and at its other or lower end 54 clampingly receives a pointer 56 which includes a covering 58 of a suitable electroluminescent phosphor and an outer covering 60 of a suitable translucent or transparent conducting substance. The numeral 62 denotes a lead secured to the outer covering 60 which communicates with a bracket 64 mounted on another shaft portion 66 which is co-axial with said shaft 49. The enlarged portion of shaft 66 is also rigidly secured to the insulator block 50. The reduced end 65 of shaft portion 66 is pivotally supported in a central recess 67 in metal bearing 68 which passes through the rear wall 69 of the cup-shaped recess 42 and is provided with a lug 70 for an electrical connection. An apertured insulating block 72 substantially all of which projects through the rear wall of cupshaped recess 42 is arranged in face-to-face relation with another apertured insulating block 73 carried by the inner face of said rear wall. As clearly shown in FIG. 8, the bearing 68 is thus arranged in out-of-metal contact with the rear wall of the cup-shaped recess 42.

The torque producing mechanism of this embodiment of the invention is as follows. An apertured, circular permanent magnet is carried by a centrally apertured bushing 81 which surrounds and rotates with the shaft portion 66. A U-shaped plate 82 (FIG. 7) is supported within the recess 42 by two terminal lugs each having an enlarged head 84. These lugs pass through and are suitably insulated from the gauge body 40. The plate 82 carries a magnetic field plate 86 secured to plate 82 by means of bent-over tabs 88. A pair of bosses 90, integral with the field plate 86, extend through apertures in the field plate. In the normal or rest position of the pointer, the poles of the circular magnet 80 align them selves with the magnetic projecting bosses 90. When current is passed through the plate 82 from one lug 84 to the other one a magnetic field is produced around the plate 82 in a direction transverse to the direction of current flow. The field plate 86' collects the magnetic flux at the central portion of the plate 82 and produces a field concentration between two bosses 90. This field concentration is orthogonal to the field produced by the magnet 80 in the rest position of the pointer. These two fields interact to produce the equivalent of a magnetic field at an angle with respect to both fields, the magnitude of this resultant angular field depends upon the relative strength of the current-produced field and the field due to the magnet. The poles of the magnet 80 align themselves with this resultant angular field thcreby producing a torque which rotates the shaft portion 66. This torque is transmitted from the shaft portion 66 to the insulator 4 block 50 and thence to the bracket 52 to thus rotate the pointer 56. It will be seen that the direction of rotation will depend upon the direction which current is passed through the plate 82 and thus the above described mechanism is suitable for a charge and discharge gauge in an automobile panel.

Having described the operation of the torque producing mechanism in this embodiment of the invention, the electrical circuitry energizing the panelescent pointer will now be described. The hot connection to the panelescent pointer and, if desired, the panelescent face 41 is made by way of exterior lug 70. Current fed into this lug passes through the bearing 68 and divides, part going to energize the face 41 through the upstanding lead 74 supported by bearing 68 to which the conductor 75 is suitably soldered. The other part of the current passes through the reduced portion of shaft 66, lug 64 and conductor 62 to the exterior coating 60 on the pointer 56. The ground connection to the pointer is made by way of contact between the metal pointer 56 and the depending leg 54, carried by bracket 52, through shaft portion 49, to bearing 47 and upstanding bracket 44 and thence to the case 40.

The operation of this embodiment of the invention is as follows. Current passing through the plate 82 produces, as above described, a torque on circular magnet 80. This torque is transmitted through bushing 81 to the enlarged portion of shaft 66. insulator 50 then rotates and turns with it stub shaft portion 49. By means of the description given above it will be understood that rotation of stub shaft portion 49 results in an oscillatory sweep of the pointer 56 over the face 41. It will be noted that the sweep of the pointer is accompanied by movement of the lead 62 attached to the lower extremity of the pointer 56 and the depending portion of bracket 64. Thus, this lead Wire 62 does not require an additional torque separate from that required to move the pointer since it is believed to be clear that it rotates through a substantially arcuate path by reason of he association of the pointer 56 with bracket 64 thereby forming a substantially integrated assembly.

Referring now to the embodiment of the invention illustrated in FIGS. 9 and 10, the numeral denotes a metallic gauge cup-shaped body having a face 102 which may be illuminated by panelescent lighting. The body 100 carries a bracket 104 which supports one leg 106 of a generally U-shaped member whose other leg 108 is of a bi-metallic material and carries a plurality of windings 11.0. The windings 110 become heated when current is passed therethrough resulting in the movement of the leg 108 due to its bi-metallic construction. The lower end of leg 108 carries a pin 112 which rides in an elongated slot in the upper portion 114 of a pointer supporting bracket 116. The left portion of an insulating block member 118 carries a shaft portion 120 rigidly secured thereto, one end of which is pivotally mounted in a depression 121 carried by the rearwardly extending leg of a bracket 128 secured to body 100. The right hand portion of block 118 carries a shaft portion 122 which is pivotally supported by an adjustable screw 124. An insulating bushing 126 surrounds the screw 124 and the former is carried by the bracket 128. The lower extremity of metallic pointer 130 is carried by a socket 131 provided at the lower end of bracket 116 and is surrounded by a coating 132 of suitable phosphorescent material which in turn is covered by a translucent or transparent conductive coating 134. A lead 136 is secured around the coating 134 and is clamped in a slit in terminal lug 137, the latter being secured to shaft portion 122 and block 118. A terminal lug 138 is in electrical contact with screw 124 and carries a lead 140.

The electrical connections to the gauge pointer are as follows. The ground connection to the pointer is made by way of bracket 116, through shaft portion 120 to its point of contact with pivot 121 and hence to the base 100 or from bracket 116 to pin 112 and arm 108 and thence to 100. The hot connection to the coating 134 is made by way of conductor 140, terminal lug 138, screw 124, shaft portion 122, terminal lug 137 and conductor 136.

The operation of this embodiment is as follows. Current, the magnitude of which varies with a condition to be sensed, passing through convolutions 110 and causes the bracket leg 108 to move in a direction away from the viewer. The accompanying movement of pin 112 riding in the slot in portion 114 of the bracket 116 causes rotation of the pointer in a clockwise direction as viewed in FIG. 9. It will be noted that the connection to the coating 134 does not, by virtue of this construction, influence the angular rotation of the pointer. If desired, the gauge face may also be illuminated by panelescent lighting.

From the foregoing description of this device it will be apparent that the gauge is of extremely simple construction and can be quickly assembled. It will be noted, more particularly from an examination of FIG. 10, that the bracket 128 provides a supporting framework for all of the elements comprising the assembly of this gauge. For example, after the elements have been integrated into a unitary structure they may be positioned into the body 100. Note that body 100 includes an apertured centering means 141 which is adapted to receive the boss 142 created by the formation of pivot 121 that supports shaft portion 120.

Referring now to the embodiment of the invention shown in FIGS. 11 to 13, the numeral .150 denotes a gauge body in the general shape of a cup. A bracket 152 extends from the body and supports, by screws 153, a gauge face 154. A panelescent pointer 156 is rotatably positioned for angular movement across the face 154 by an actuating mechanism 158. The latter includes a U-shaped bi-metallic member 159 whose leg 160 is surrounded by a resistance heating coil 162. The ends of the coil are secured to insulated terminals 164 and 166 set in a fibrous insulating element 168. A bracket 170, formed with two legs having aligned apertures, is provided with an extension 172 which clampingly engages the lower end of the pointer 156. The leg 160 carries a pin 161 slidably positioned within a slot 174 in bracket 170. Shaft 176 passes through the aligned apertures in bracket 170 and retains the latter by means of a head 178.

The pointer is coated with a suitable electro-luminescent phosphor (not illustrated) over which lies a conductive coating of a transparent or translucent substance. A lead 180 is secured to this outer coating and is connected to terminal 182 fed by lead 184. The terminal includes an extension 186 which passes through insulating grommet 188 in face 154 and whose end bears against a small insulating pad 190.

As indicated by the layers shown at FIG. 13, the gauge face 154 may also be illuminated by panelescence.

In the operation of this embodiment, current, the magnitude of which varies with a condition to be sensed, passes through terminals 164, 166 and coil 162 heats the leg 160. This leg then turns away from the reader (in FIG. 12), the pin 161 bearing against an edge of slot 174, moving relative thereto and causing the bracket 170 to rotate about shaft 176, the pointer 156 sweeping across the face.

The phosphor is excited by an electric field supplied by lead 184 and the case, the latter communicating with the body of the pointer through the lower end of bracket 172.

I claim:

1. A panelescent gauge construction comprising an electro-conductive shaft, and electro-conductive pointer carried by said shaft, means for rotatably mounting the shaft on the gauge, an electroluminescent phosphor coating on the said pointer, a conductive, translucent coating on said phosphor coating, an insulating member on said shaft, a spring element mounted on said insulating member to bias rotation of said shaft, means holding said spring relative to said gauge and connectable to an electric current source, means electrically joining said translucent coating to said spring, and means including said shaft connectable to electric ground, whereby rotation of the shaft is resisted only by said spring.

2. A panelescent gauge construction comprising a hollow bushing, a supporting bracket threadedly receiving said hollow bushing, an electro-conductive shaft rotatably received within said bushing, an electro-conductive pointer connected to one end of the shaft, a torque mechanism for turning the pointer, an electroluminescent phosphor coating on a portion of said pointer, a second coating on said pointer overlying a portion of said phosphor coating, said second coating being conductive and translucent, an insulating bushing clamped on said shaft intermediate said pointer and said hollow bushing, a spiral spring having its ccntermost end mounted on said insulating bushing, a lead connecting said second pointer coating to a portion of said spring, a spring tension clip of insulator material carried by said hollow bushing for rotary adjustment thereabont, a terminal carried by said clip having two-portions, one portion of the terminal receiving one end of said spring, the other portion of said terminal connectable to an electric current source, and means including said shaft for connecting said pointer to electrical ground whereby the phosphor is excitable by a field between the pointer and second coating and rotation of the pointer is resisted only by the spring.

3. A panelescent gauge construction comprising a casing, a shaft rotatably carried by said casing, a pointer carried by said shaft, an electroluminescent phosphor coating on said pointer, a conductive coating overlying a portion of said phosphor coating, a lead connected at one end thereof to said conductive coating for energization thereof, an insulating member carried by said shaft, a torsion bias element having one end fixed to said insulating member, a lead connected at one end thereof to said conductive coating and at its other end to said torsion bias element, and means fixing the other end of said torsion bias element from rotation with respect to said shaft and for connecting said torsion bias element to an electric current source.

4. The structure of claim 3 wherein the stationary end of the said bias element is angularly adjustable with respect to the said shaft, whereby the bias on the shaft may be varied.

References Cited in the tile of this patent UNITED STATES PATENTS 2,566,349 Mager Sept. 4, 1951 2,624,857 Mager Jan. 6, 1953 2,702,340 Thieblot Feb. 15, 1955 2,755,457 Diemer July 17, 1956 2,791,723 Nagy May '7, 1957 2,792,803 Hardesty May 21, 1957 2,858,632 Caserio Nov. 4, 1958 2,949,596 Levene Aug. 16, 1960 

1. A PANELESCENT AUGE CONSTRUCTION COMPRISING AN ELECTRO-CONDUCTIVE SHAFT, AND ELECTRO-CONDUCTIVE POINTER CARRIED BY SAID SHAFT, MEANS FOR ROTATABLE MOUNTING THE SHAFT ON THE GAUGE, AN ELECTROLUMINESCENT PHOSPHOR COATING ON THE SAID POINTER, A CONDUCTIVE, TRANSLUCENT COATING ON SAID PHOSPHER COATING, INSULATING MEMBER ON SAID SHAFT, A SPRING ELEMENT MOUNTED ON SAID INSULATING MEMBER TO BIAS ROTATION OF SAID SHAFT, MEANS HOLDING SAID SPRING RELATIVE TO SAID GAUGE AND CONNECTABLE TO AN ELECTRIC CURRENT SOURCE, MEANS ELECTRICALLY JOINING SAID TRANSLUCENT COATING TO SAID SPRING, AND MEANS INCLUDING SAID SHAFT CONNECTABLE TO ELECTRIC GROUND, WHEREBY ROTATION OF THE SHAFT IS RESISTED ONLY BY SAID SPRING. 